Culver Joseph P, Durduran Turgut, Furuya Daisuke, Cheung Cecil, Greenberg Joel H, Yodh A G
Department of Physics and Astronomy, Cerebrovascular Research Center, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A.
J Cereb Blood Flow Metab. 2003 Aug;23(8):911-24. doi: 10.1097/01.WCB.0000076703.71231.BB.
Diffuse optical tomography (DOT) is an attractive approach for evaluating stroke physiology. It provides hemodynamic and metabolic imaging with unique potential for continuous noninvasive bedside imaging in humans. To date there have been few quantitative spatial-temporal studies of stroke pathophysiology based on diffuse optical signatures. The authors report DOT images of hemodynamic and metabolic contrasts using a rat middle cerebral artery occlusion (MCAO) stroke model. This study used a novel DOT device that concurrently obtains coregistered images of relative cerebral blood volume (rCBV), tissue-averaged hemoglobin oxygen saturation (Sto(2)), and relative cerebral blood flow (rCBF). The authors demonstrate how these hemodynamic measures can be synthesized to calculate an index of the oxygen extraction fraction (OEF) and the cerebral metabolic rate of oxygen consumption (CMRo(2)). Temporary (60-minute) MCAO was performed on five rats. Ischemic changes, averaged over the 60 minutes of occlusion, were as follows: rCBF = 0.42 +/- 0.04, rCBV = 1.02 +/- 0.04, DeltaSto(2) = -11 +/- 2%, rOEF = 1.39 +/- 0.06 and rCMRo(2) = 0.59 +/- 0.07. Although rOEF increased in response to decreased blood flow, rCMRo(2) decreased. The sensitivity of this method of DOT analysis is discussed in terms of assumptions about baseline physiology, and the diffuse optical results are compared with positron emission tomography, magnetic resonance imaging, and histology observations in the literature.
扩散光学断层扫描（DOT）是一种评估中风生理状况的有吸引力的方法。它能提供血流动力学和代谢成像，在对人类进行连续无创床边成像方面具有独特潜力。迄今为止，基于扩散光学特征对中风病理生理学进行的定量时空研究很少。作者报告了使用大鼠大脑中动脉闭塞（MCAO）中风模型获得的血流动力学和代谢对比的DOT图像。本研究使用了一种新型DOT设备，可同时获取相对脑血容量（rCBV）、组织平均血红蛋白氧饱和度（Sto(2)）和相对脑血流量（rCBF）的配准图像。作者展示了如何综合这些血流动力学测量值来计算氧摄取分数（OEF）和脑氧代谢率（CMRo(2)）指标。对五只大鼠进行了短暂（60分钟）的MCAO。在60分钟闭塞期间的平均缺血变化如下：rCBF = 0.42 +/- 0.04，rCBV = 1.02 +/- 0.04，ΔSto(2) = -11 +/- 2%，rOEF = 1.39 +/- 0.06，rCMRo(2) = 0.59 +/- 0.07。尽管rOEF因血流量减少而增加，但rCMRo(2)却降低了。本文根据对基线生理学的假设讨论了这种DOT分析方法的敏感性，并将扩散光学结果与文献中的正电子发射断层扫描、磁共振成像和组织学观察结果进行了比较。
